Change color of polygon when setting point into it

[Grizou79]

I have several polygons. When a point is placed inside a polygon, it should turn red. I can achieve this with rule-based styling, but it only works for the current state when I set the formatting or manually refresh. I would like the polygon to change color the moment I place a point inside it. Is that possible?

[Grizou79]

It is possible...it already worked, just made a mistake...